Under the current logic, when gc_urgent_high_remaining is set to 1,
the mode will be switched to normal at the beginning, instead of
running in gc_urgent mode.
Let's switch the gc mode back to normal when the gc ends.
Fixes: 265576181b4a ("f2fs: remove gc_urgent_high_limited for cleanup")
Signed-off-by: Yangtao Li <frank.li@xxxxxxxx>